字典 -- 数据结构与算法的javascript描述 第七章

字典

字典是一种以键-值对形式存储数据的数据结构

最基本功能规划

add    添加数据到字典
remove  从字典中移除数据
get  从字典中取出数据
count  统计字典数据量
find   查找数据在字典中位置
show  显示字典数据

 /**
     * 字典
     * @constructor
     */
    function Dictionary(){
        var me = this;
        me.dataStore = [];
        me.add = add;
        me.find = find;
        me.remove = remove;
        me.clear = clear;
        me.count = count;
        me.showAll = showAll;

        function add(key,value){
            me.dataStore[key] = value;
        }
        function find(key){
            return me.dataStore[key] ;
        }
        function remove(key){
            delete me.dataStore[key]
        }
        function clear(){
            for(var i in Object.keys(me.dataStore)){
                delete me.dataStore[i];
            }
        }
        function showAll (){
            var list = Object.keys(me.dataStore).sort(),s=' ';
            list.forEach(function(item){
                s+= "key: "+item;
                s+= ",value: "+me.dataStore[item] +" 
 "
            })
            console.log(s)
        }
        function count(){
            var list = Object.keys(me.dataStore),n=0;
            list.forEach(function(){
                ++n;
            })
            return n;
        }

    }

test

var pbook = new Dictionary();
    pbook.add("Raymond","123");
    pbook.add("David", "345");
    pbook.add("Cynthia", "456");
    pbook.add("Mike", "723");
    pbook.add("Jennifer", "987");
    pbook.add("Danny", "012");
    pbook.add("Jonathan", "666");
    pbook.add("Accccc", "666");
    pbook.showAll();
    console.log(pbook.find('Accccc'))
    console.log(pbook.count())

    //提取字符出现次数
var s = "the brown fox jumped over the blue fox";

    var stotal = new Dictionary();
    var sarr = s.split(' ');
    for(var i = 0,n= sarr.length;i<n;i++){
        if(stotal.find(sarr[i])){
           var v = stotal.find(sarr[i]);
            stotal.remove(sarr[i])
            stotal.add(sarr[i],v+1)
        }else{
            stotal.add(sarr[i],1)
        }
    }
    stotal.showAll();